Influence of Repeat Intervention on the Risk of Major Amputation After Infrapopliteal Angioplasty for Critical Limb Ischemia

Purpose: To assess the influence of repeat intervention on the risk of major amputation after infrapopliteal angioplasty for patients with critical limb ischemia (CLI). Methods: A multicenter database of Japanese CLI patients was interrogated to identify patients who underwent balloon angioplasty for isolated infrapopliteal lesions from April 2004 to December 2012. In that time frame, 1298 limbs of 1065 patients (mean age 72 +/- 10 years; 739 men) were eligible for this analysis. The prevalence of tissue loss was 76%, with 33% accompanied by infection. The association between repeat intervention and future risk for major amputation was evaluated using a mixed effects logistic regression model. A stratification analysis was also performed with baseline variables. A supplementary analysis compared baseline characteristics between the cases with and without repeat intervention. Hazard ratios (HR) and their 95% confidence intervals (CI) are reported. Results: Median follow-up was 1.2 years (interquartile range 0.4-2.5), during which time 143 (11.0%) limbs had major amputations and 499 (38.4%) underwent repeat intervention. The mixed effects modeling revealed that repeat intervention was significantly associated with future risk for major amputation (unadjusted HR 3.01, 95% CI 2.05 to 4.41, p=0.001). From the stratification analysis, repeat intervention significantly increased future risk of major amputation in cases with regular dialysis (HR 3.35, 95% CI 2.14 to 5.26, p<0.001), whereas it did not in those without dialysis. The supplemental analysis showed that patients with repeat intervention within 1 year had a higher prevalence of nonambulatory status, regular dialysis, tissue loss, and infection at baseline compared to those without repeat intervention for 1 year. Conclusion: In the patients with CLI due to infrapopliteal lesions, the need for repeat intervention increased the risk of future major amputation. However, this correlation was not applicable to nondialysis patients.